The roster of the richest, released today, saw Microsoft Chairman Bill Gates return to the top spot with a total net worth of $40 billion, despite losing a staggering $12 billion over the last 12-months.

Warren Buffett slips to #2 richest person after losing $25 billion this year (he's still worth $37 billion). Mexican telecom tycoon Carlos Slim Helu also lost about $25 billion this year, but came in third on the richest list with a $35 billion net worth.

The total net worth of this year's 793 billionaires is $2.4 trillion - down from $4.4 trillion last year, according to Forbes. Of the top 20, 10 are Americans. New York CityMayor Michael Bloomberg (#17) was the only person in the top 20 to turn a profit this year after he bought a 20% stake in Merrill Lynch.

While 656 moguls lost money in the past year, 44 added to their fortunes, Forbes said. Last year's biggest gainer, India's Anil Ambani (#34) was also this year's biggest loser with $32 billion of his fortune disappearing this past year.

Russia also saw a significant drop in billionaire representation with nearly two thirds of its richest falling out of the billionaire's club.